NR2E3 and retinal degeneration: Mice lacking Nr2e3, Nr2e3rd7/rd7, rd7, exhibit a slow progressive retinal degeneration, characterized clinically by pan-retinal spotting, and histologically by whorls and rosettes due to excess production of blue opsin expressing cone cells followed by progressive degeneration of both rod and cone photoreceptor cells41, 47, 48.